Solve the equation $2x+4=0$ by graphing.

1.

Graph the left side of the expression in a coordinate system, $y=2x+4$.

2.

Graph the right side of the expression in a coordinate system, $y=0$.

3.

Mark the point where the graphs intersect. It will look like this:

4.

Read off the $x$-value of the intersection. From the figure you can see that the graphs intersect in $x=-2$.

Solve the equation $x^2=4$ by graphing.

1.

Graph the left side of the expression in a coordinate system, $y=x^2$.

2.

Graph the right side of the expression in the coordinate system, $y=4$.

3.

Mark the points where the graphs intersect. Your coordinate system will now look like this:

4.

Read off the $x$-values at the intersections. You can see in the figure that the graphs intersect at $x_1=-2$ and $x_2=2$. That means the solution is $x=\pm 2$.